Manufacturing paints by mixing pre-paint modules has been discussed in the patent literature. For example, U.S. Pat. No. 5,672,649 to Brock et al discloses five or more modules for making special effect paints, including (a) special effect module, (b) binder module, (c) dye module, (d) rheology module and (e) cross-linking module. Four modules contain various binders and the fifth module may also contain binder. The special effect module and the dye module contain pigments.
U.S. Pat. No. 6,221,145 to McClain and its progenies, i.e., subsequent cases that claims priority thereto, disclose manufacturing paints at the point of sale by mixing four pre-paints, including (a) pigment module, (b) dispersant thickener/diluent module, (c) low resin module and (d) high resin module. The low resin module contains a number of extender pigments as well as resin and the pigment module may contain small amount of resin. Progeny U.S. Pat. No. 7,339,000 to McClain et al further explains that the four modules can be varied to produce various color bases so that they are suitable for use to make different paint colors. Progeny U.S. Pat. No. 7,919,546 to Trevino et al adds an extender pre-paint and teaches that the pre-paints can be varied to produce paints with various tint bases so that they are suitable for use to form different types of color paints. Trevino also discloses that every formula or recipe for every base paints can be entered into a database for the retail paint production apparatus to produce all the paints that can be produced at the factories. McClain and its progenies do not disclose simple manufacturing process at the point of sale.
U.S. Pat. No. 6,531,537 to Friel et al teaches another point of sale paint manufacturing technique, which has three principal pre-paints: (i) opacifying pre-paint, (ii) extender pre-paint, and (iii) binder pre-paint. Properties of the paint, such as sheens/finishes, tint bases, etc., can be varied at the point of sale when these three pre-paints are mixed with one or more of the same pre-paints. Friel acknowledges that point of sale manufacturing has its drawbacks, including inconsistent key properties of paints, such as viscosity, gloss or color. Friel proposes to test for the key properties through feedback loops in the paint making machine to ensure that these properties are controlled.
Presently, commercial paint manufacturing at the point of sale requires complex machineries at the retail stores. The manufacturing process has been shifted from the factory to the retail spaces, but without the quality controls and assurances that are provided by trained chemists and technicians. The control of bio-organisms that can live in aqueous paint compositions or precursors thereof is not clearly understood. Premature cross-linking of latexes in the aqueous phase during storage is not addressed. The disposal of waste and byproducts, such as pigment clumping and solidified paint films which must be handled in accordance to local disposal ordinances, is left to the retailers. Maintenance and cleaning of the manufacturing equipment must still be done by trained technicians. The manufacturing challenges that are typically handled by plants and factories are delegated to the retail levels with potentially undertrained operators.
The expected space saving and reduction in inventory are still unrealized, due to the complexities of the paint manufacturing now being proposed for the retail stores. Large tanks of precursor liquids must be stored, as well as the colorants and empty paint cans and buckets. Retail space must be reserved for the paint making machineries. FIG. 1 illustrates the paint manufacturing at the point of sale or the retail level, where empty cans or container 1 is filled with a number of premixes or pre-paint modules to make paints.
On the other hand, traditional retail paint stores typically carry factory-made tintable paints that can be mixed with colorants to make paints in five finishes (flat, matte, eggshell, satin and semi-gloss). Tintable paints can be classified into four bases, such as white, pastel/light, deep, or medium/mid-tone. Each base contains a different amount of opacifying pigments, such as titanium dioxide. Final paint colors depend significantly on the amount of TiO2 white pigments in the tintable base. For example, deep colors require lower amounts of TiO2 while pastel colors require higher amounts of TiO2. White and medium bases likewise have different levels of TiO2. To produce a wide variety of paint colors, retail stores generally need to store tintable paints in five finishes and four bases (1 base-4 base), i.e., about 20 different tintable base paints for each paint line. Paint lines are generally based on the paint quality, e.g., from premium lines to economy lines, ultra-low VOC paints, stains and specialty paints and coatings.
In one example, the color prescriptions for one particular color for various sheens/finishes for a single paint line vary depending on the amount of opacifying pigments contained in the bases.
1 Base, 4 FinishesExemplary Color(Pounds of TiO2Prescriptionsper 100 gallons)for a Single ColorSemi-Gloss 1 BaseMagenta 0 × 19(283 lbs.)Blue 0 × 17Red 0 × 3Pearl/satin 1 BaseMagenta 0 × 15(202 lbs.)Blue 0 × 18Red 0 × 2.5Eggshell 1 BaseYellow 0 × 7(269 lbs.)Magenta 0 × 24Blue 0 × 18Matt 1 BaseMagenta 0 × 17.5(218 lbs.)Blue 0 × 17Red 0 × 2Flat 1 BaseMagenta 0 × 18.5(210 lbs.)Blue 0 × 16.5Red 0 × 2.5The remaining three tintable bases would have their own set of color prescriptions for the same color. Carrying up to 20 or more different tintable paints for each paint line requires significant storage at the traditional retail stores, and 20 different color prescriptions for each single color.
Hence, there remains a need to simplify the preparation of paints at the points of sale or points of use and to reduce the required storage of traditional paint stores.